package day07;


import java.util.Random;
import java.util.Scanner;

/**
 * 需求：生成4位的验证码（大写字母、小写字母、数字）
 */

public class VerificationCode {
    public static void main(String[] args) {
        String code=generateVerificationCode(6);
        System.out.println("6位验证码为："+code);
         String upper=code.toUpperCase();
        Scanner scanner=new Scanner(System.in);
        System.out.println("请输入验证码");
String verifi=scanner.next();
String upperVerifi= verifi.toUpperCase();
if (upper.equals(upperVerifi)){
    System.out.println("验证码正确");
}else {
    System.out.println("验证码错误");
}

    }
    //生成验证码
    public static String generateVerificationCode(int len){
        String code="";
        //...
        char[] chs={'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o',
        'p','q','r','s','t','u','v','w','x','y','z','A','B','C','D','E','F','G',
        'H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z',
        '0','1','2','3','4','5','6','7','8','9'};
        Random rand=new Random();
        for (int i=1;i<=len;i++){//len次
//            int index=(int)(Math.random()*chs.length);//随机下标0-61



            int index=rand.nextInt(chs.length);//随机下标[0-61]
            System.out.println(index);
            code+=chs[index];//获取随机字符并拼接到code中
        }
        return code;
        /*
        i=1 true index=25 z
        i=2 true index=26 A
        i=3 true index=30 F
         */

    }
}
